The present disclosure relates to a copper plating solution and a copper plating method.
Plating technologies have been used in almost every field ranging from daily necessities to high tech products. Almost every article, such as metallic articles and plastic articles, can be plated. Among them, an article made of aluminum or an aluminum alloy is very easily oxidized. Even if an oxide film on its surface is removed by immersing the article in acid, another oxide film will be formed again in a subsequent washing process. Thus, if this article were pretreated (activated) by a common technique before plating, the resulting plated layer would be less adhesive. Therefore, in general, aluminum or an aluminum alloy is pretreated with zincate before plating.
A zincate treatment is a zincate conversion process, in which aluminum or an aluminum alloy is immersed in a strong alkaline zinc solution to dissolve an aluminum oxide film, and deposit zinc on the exposed surface of aluminum. An aluminum article treated with zincate one time has large-diameter zinc particles deposited sparsely on its surface. Thus, if a different kind of metal is plated thereon, the adherence of such metal does not improve significantly. Therefore, in general, a double zincate treatment in which the zincate treatment is performed twice is conducted.